A conventional regulation approach to maintain constant liquid pressure in a human body is manually operated. For example, when a patient is in circulatory shock, a healthcare provider would measure central venous pressure (CVP) of the patient by connecting a central venous catheter to the inferior vena cava of the patient to obtain a measured pressure value, and supply normal saline into the inferior vena cava via the central venous catheter if the measured pressure value is smaller than a target pressure value. The process of measuring the CVP and the process of supplying normal saline are performed alternately until the measured pressure value increases to the target pressure value or until the normal saline supplied thus far reaches a predetermined amount. The conventional regulation approach generally takes more than an hour, and a dedicated healthcare provider is ideally required. However, due to shortage of manpower in hospitals, the healthcare provider is often busy and multi-tasking, leaving the patient at risk of being oversupplied with normal saline.
Similarly, for a patient who suffers from increased intracranial pressure (ICP) due to traumatic brain injury, stroke or brain tumor, conventional treatment is to connect a catheter to a ventricle of the patient's brain so as to drain cerebrospinal fluid (CSF) from the ventricle for lowering the ICP. The ICP is measured once an hour via the catheter connected to the ventricle, and three to five milliliters of the CSF is drained from the ventricle when a value of the ICP thus measured is greater than a target value. The process of measuring the ICP and the process of draining the CSF are performed alternately until the value of the ICP decreases to the target value or until the drainage accumulated over time reaches a predetermined amount ranging from ten to fifteen milliliters. The conventional treatment takes roughly ten minutes every hour and lasts for several days. Therefore, not only is the conventional treatment time-consuming, but risk of overdrainage is also likely unavoidable under a condition of manpower shortage.